Using the Fast Twain Feature

Take the following steps to start a project and to add some code that acquires the images using Fast Twain:

Start Visual Studio.
Choose File->New->Project… from the menu.
In the New Project dialog box, choose either "Visual C# Projects" or "VB Projects" in the Projects Type List, and choose "Windows Application" in the Templates List.
Type the project name as "UsingFastTwainFeature" in the Project Name field, and then choose OK. If desired, type a new location for your project or select a directory using the Browse button, and then choose OK.
In the "Solution Explorer" window, right-click on the "References" folder, and select "Add Reference…" from the context menu. In the "Add Reference" dialog box, select the ".NET" tab and browse to Leadtools For .NET "<LEADTOOLS_INSTALLDIR>\Bin\Dotnet\Win32" folder and select the following DLLs:
- Leadtools.dll
- Leadtools.Twain.dll
- Leadtools.Codecs.dll
- Leadtools.WinForms.dll
Click the Select button and then press the OK button to add the above DLLs to the application.

Go to the toolbox (View->Toolbox) and Drag and drop 2 instances of RadioButton control to the top of the form and set the following properties for them:

Text	Name	Checked
Native	radioNative	False
Memory	radioMemory	False

Go to the toolbox (View->Toolbox) and Drag and drop a 1 instance of Button control to the top of the form and set the following properties for them:

Text Name

Fast Acquire buttonFastAcquire
Go to the toolbox (View->Toolbox) and Drag and drop an instance of Check Box control to the top of the form and set the following properties for them:

Name Name

Use Buffer Size checkBoxUseBufferSize
Go to the toolbox (View->Toolbox) and Drag and drop 2 instances of Text Box control to the top of the form and change the following properties:

Property Value

Name textBufferSize

Name textFileName

Text	Name
Fast Acquire	buttonFastAcquire

Name	Name
Use Buffer Size	checkBoxUseBufferSize

Property	Value
Name	textBufferSize
Name	textFileName

Switch to Form1 code view (right-click Form1 in the solution explorer then select View Code) and add the following lines at the beginning of the file:

Imports Leadtools 
Imports Leadtools.Twain 
Imports Leadtools.Codecs 
Imports Leadtools.WinForms

using Leadtools; 
using Leadtools.Twain; 
using Leadtools.Codecs; 
using Leadtools.WinForms;

Declare the following private variable:

Private WithEvents twnSession As TwainSession

private TwainSession twnSession;

Add an event handler to the Form1 Load event and code it as follows:

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
   textFileName.Text = "c:\twain_test.tif" 
   textBufferSize.Text = "2048" 
   Try 
      ' Unlock Document support. 
      ' Note that this is a sample key, which will not work in your toolkit. 
      Dim MY_LICENSE_FILE As String = "d:\temp\TestLic.lic" 
      Dim MY_DEVELOPER_KEY As String = "xyz123abc" 
      RasterSupport.SetLicense(MY_LICENSE_FILE, MY_DEVELOPER_KEY) 
      twnSession = new TwainSession 
      twnSession.Startup(Me.Handle, "manufacturer", "productFamily", "version", "application", TwainStartupFlags.InitializeMultithreaded) 
   Catch ex As Exception 
      MessageBox.Show(ex.Message) 
   End Try 
End Sub

private void Form1_Load(object sender, System.EventArgs e) 
{ 
   textFileName.Text = @"c:\twain_test.tif"; 
   textBufferSize.Text = "2048"; 
   try 
   { 
      // Unlock Document support. 
      // Note that this is a sample key, which will not work in your toolkit. 
      string MY_LICENSE_FILE = "d:\\temp\\TestLic.lic"; 
      string MY_DEVELOPER_KEY = "xyz123abc"; 
      RasterSupport.SetLicense(MY_LICENSE_FILE, MY_DEVELOPER_KEY); 
      twnSession = new TwainSession(); 
      twnSession.Startup(this.Handle, "manufacturer", "productFamily", "version", "application", TwainStartupFlags.InitializeMultithreaded); 
   } 
   catch (Exception ex) 
   { 
      MessageBox.Show(this, ex.Message); 
   } 
}

Add an event handler to the Form1 Closing event and code it as follows:

Private Sub Form1_FormClosing(ByVal sender As System.Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles MyBase.FormClosing 
   Try 
      twnSession.Shutdown() 
   Catch ex As Exception 
      MessageBox.Show(ex.Message) 
   End Try 
End Sub

private void Form1_FormClosing(object sender, FormClosingEventArgs e) 
{ 
   try 
   { 
      twnSession.Shutdown(); 
   } 
   catch (Exception ex) 
   { 
      MessageBox.Show(this, ex.Message); 
   } 
}

Add an event handler to the buttonFastAcquire Click event and code it as follows:

Private Sub buttonFastAcquire_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles buttonFastAcquire.Click 
   Dim transferMode As TwainTransferMode 
   Dim transferFormat As RasterImageFormat 
   If radioMemory.Checked Then 
      transferMode = TwainTransferMode.Buffer 
      transferFormat = RasterImageFormat.CcittGroup4 
   Else 
      transferMode = TwainTransferMode.Native 
      transferFormat = RasterImageFormat.Tif 
   End If 
   Try 
      twnSession.AcquireFast(textFileName.Text, _ 
                             TwainFastUserInterfaceFlags.Show Or TwainFastUserInterfaceFlags.UseThread, _ 
                             transferMode, _ 
                             transferFormat, _ 
                             1, _ 
                             True, _ 
                             Convert.ToInt32(textBufferSize.Text), _ 
                             checkBoxUseBufferSize.Checked) 
   Catch ex As Exception 
      MessageBox.Show(ex.Message) 
   End Try 
End Sub

private void buttonFastAcquire_Click(object sender, System.EventArgs e) 
{ 
   TwainTransferMode transferMode; 
   RasterImageFormat transferFormat; 
   if (radioMemory.Checked) 
   { 
      transferMode = TwainTransferMode.Buffer; 
      transferFormat = RasterImageFormat.CcittGroup4; 
   } 
   else 
   { 
      transferMode = TwainTransferMode.Native; 
      transferFormat = RasterImageFormat.Tif; 
   } 
   try 
   { 
      twnSession.AcquireFast(textFileName.Text, 
                             TwainFastUserInterfaceFlags.Show |   TwainFastUserInterfaceFlags.UseThread, 
                             transferMode, 
                             transferFormat, 
                             1, 
                             true, 
                             Convert.ToInt32(textBufferSize.Text), 
                             checkBoxUseBufferSize.Checked); 
   } 
   catch (Exception ex) 
   { 
      MessageBox.Show(ex.Message); 
   } 
}